This invention relates to an 8-(substituted)alkoxy-4-oxoquinoline-3-carboxylic acid derivative having 3-(S)-amino-4-(S)-fluoromethylpyrrolidin-1-yl group at the 7-position of the quinoline nucleus as a substituent, which has excellent antibacterial activity, good pharmacokinetics and high safety, and to an antibacterial agent and an antibacterial preparation, which contain the compound.
This invention also relates to a compound which is useful for introducing a substituent at the 7-position that has such a structure that excellent antibacterial activity, pharmacokinetics and safety can be added to synthetic quinolone antibacterial agents in which the structure of the substituent at the 7-position exerts important influences upon the antibacterial activity, pharmacokinetics and safety.
Since the discovery of norfloxacin, antibacterial activity and pharmacokinetics of quinolone synthetic antibacterial agents have been improved, and many compounds are now used in the clinical field as chemotherapeutic agents which are effective in almost systemic infectious diseases.
In recent years, generation of bacteria having low sensitivity to quinolone synthetic antibacterial agents has been increasing in the field of clinics. For example, like the case of Staphylococcus aureus (MRSA) which is non-sensitive to xcex2-lactam antibiotics, a case has been increasing in which a bacterium originally resistant to drugs other than quinolone synthetic antibacterial agents becomes low-sensitive to quinolone synthetic antibacterial agents too. In consequence, development of a drug having further high efficacy has been called for in the field of clinics. On the other hand, it has been revealed that quinolone synthetic antibacterial agents cause a side effect in which severe convulsion is induced when a non-steroidal anti-inflammatory drug is simultaneously used, as well as other side effects such as phototoxicity and the like, so that development of a quinolone synthetic antibacterial agent having higher safety has also been called for in the field.
Quinolone-carboxylic acid derivatives which has the cis-3-amino-4-fluoromethylpyrrolidin-1-yl group related to the present invention as a substituent are disclosed for example in JP-A-62-19583, JP-A-63-45261 and JP-A-63-152318 (the term xe2x80x9cJP-Axe2x80x9d as used herein means an xe2x80x9cunexamined published Japanese patent applicationxe2x80x9d), and these patents describe compounds represented by the following formula. However, though the substituent at the 7-position of these disclosed quinolones is a cis-3-amino-4-fluoromethylpyrrolidin-1-yl group, they are compounds which have the 8-fluoroquinoline nucleus in which the 8-position substituent is a halogen atom, and nothing is described about a compound which has the 8-methoxyquinoline nucleus related to the present invention. In addition, there is no illustrative disclosure in these specifications concerning an optically active compound 3-(S)-amino-4-(S)-fluoromethylpyrrolidine or 3-(S)-amino-4-(S)-fluoromethylpyrrolidinyl group. 
(In the above formula, R5 is a hydrogen atom or a fluorine atom. Definition of the substituent of the compound represented by the formula (III) is unrelated to the compound of the present invention.)
In addition, JP-A-3-188074 discloses a compound represented by the following formula (IV), but it does not disclose a compound which has the 1-cyclopropyl-8-methoxyquinoline nucleus related to the present invention. Also, there is no illustrative disclosure in the specification concerning an optically active compound 3-(S)-amino-4-(S)-fluoromethylpyrrolidine or 3-(S)-amino-4-(S)-fluoromethylpyrrolidinyl group. 
(In the above formula, R6 is a hydrogen atom or an amino group. Definition of the substituent of the compound represented by the formula (IV) is unrelated to the compound of the present invention.)
Also, JP-A-4-211077 discloses a compound which has the 1-cyclopropyl-8-methoxyquinoline nucleus, represented by the following formula (V). However, there is no illustration in the specification concerning a compound substituted with 3-(S)-amino-4-(S)-fluoromethylpyrrolidinyl group. 
(In the above formula, R7 is methyl, ethyl or the like lower alkyl group. Definition of the substituent of the compound represented by the formula (V) is unrelated to the compound of the present invention.)
In addition, there is no description in the just described specification about safety of a compound represented by the following formula (VI) in which R7 is a methyl group. 
The inventors of the present invention have carried out tests on the safety of the compound represented by the formula (VI) and found as the result that its mouse peripheral blood micronucleus test was positive (micronucleus inducing action).
The present inventors have conducted intensive studies with the aim of providing a compound which has excellent antibacterial activity, high efficacy and excellent safety in the clinical field. As the result, it has been found that an 8-methoxyquinoline compound substituted with 3-(S)-amino-4-(S)-fluoromethylpyrrolidin-1-yl group, represented by the following formula (I), is superior to its corresponding 8-methoxyquinoline compound substituted with 3-(S)-amino-4-(S)-methylpyrrolidin-1-yl group, represented by the aforementioned formula (VI), thereby resulting in the accomplishment of the present invention.
That is, it has been found that the compound represented by the following formula (I) is possessed of excellent antibacterial activity upon a broad range of Gram-negative and Gram-positive bacteria and have excellent safety and pharmacokinetics, such as its micronucleus test-negative property. 
[In the above formula, R1 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, wherein the alkyl group may have one or more substituent(s) selected from the group consisting of a hydroxyl group, a halogen atom, an alkylthio group having 1 to 6 carbon atoms and an alkoxyl group having 1 to 6 carbon atoms,
R2 represents a halogenomethoxyl group or an alkoxyl group having 1 to 6 carbon atoms,
R3 represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a halogenoalkyl group having 1 to 6 carbon atoms, a cyclic alkyl group having 3 to 6 carbon atoms which may have a substituent, a heteroaryl group which may have a substituent, an alkoxyl group having 1 to 6 carbon atoms or an alkylamino group having 1 to 6 carbon atoms, and
R4 represents a hydrogen atom, a phenyl group, an acetoxymethyl group, a pivaloyloxymethyl group, an ethoxycarbonyl group, a choline group, a dimethylaminoethyl group, a 5-indanyl group, a phthalidinyl group, a 5-alkyl-2-oxo-1,3-dioxol-4-ylmethyl group, 3-acetoxy-2-oxobutyl group, an alkyl group having 1 to 6 carbon atoms, an alkoxylmethyl group having 2 to 7 carbon atoms or a phenylalkyl group composed of an alkylene group having 1 to 6 carbon atoms and a phenyl group.
In this connection, the substituent R4 may also be a boron-containing group represented by the following formula:
xe2x88x92B(Y11)Y12
wherein Y11 and Y12, each independently represents a fluorine atom or an alkylcarbonyloxy group having 2 to 4 carbon atoms.]
Accordingly, the present invention relates to a compound represented by the aforementioned formula (I), its salts or hydrates thereof.
The present invention also relates to the aforementioned 8-methoxyquinolone-carboxylic acid derivative, its salts or hydrates thereof in which the compound of formula (I) is a stereochemically pure compound;
the aforementioned compound, its salts or hydrates thereof, wherein R1 in the formula (I) is a hydrogen atom;
the aforementioned compound, its salts or hydrates thereof, wherein R2 in the formula (I) is a methoxyl group; 7-[3-(S)-amino-4-(S)-fluoromethyl-1-pyrrolidinyl]-1-cyclopropyl-6-fluoro-1,4-dihydro-8-methoxy-4-oxoquinoline-3-carboxylic acid, its salts or hydrates thereof, wherein R3 in the formula (I) is a cyclopropyl group;
the aforementioned compound, its salts or hydrates thereof, wherein R3 in the formula (I) is a halogenocyclopropyl group;
the aforementioned compound, its salts or hydrates thereof, wherein R3 in the formula (I) is a 1,2-cis-halogenocyclopropyl group;
the aforementioned compound, its salts or hydrates thereof, wherein R3 in the formula (I) is a stereochemically pure substituent;
the aforementioned compound, its salts or hydrates thereof, wherein R3 in the formula (I) is a (1R,2S)-2-halogenocyclopropyl group;
7-[3-(S)-amino-4-(S)-fluoromethyl-1-pyrrolidinyl]-6-fluoro-1-[2-(S)-fluoro-1-(R)-cyclopropyl]-1,4-dihydro-8-methoxy-4-oxoquinoline-3-carboxylic acid, its salts or hydrates thereof, wherein R3 in the formula (I) is a (1R,2S)-2-fluorocyclopropyl group;
a medicament which comprises the aforementioned compound, a hydrate thereof, a salt of the compound or a hydrate of the salt as an active ingredient; and
an antibacterial agent or antibacterial preparation which comprises the aforementioned compound, a hydrate thereof, a salt of the compound or a hydrate of the salt as an active ingredient.
The present invention also relates to a compound represented by the following formula (II), its salts or hydrates thereof: 
(wherein R11 and R12 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a protective group of the amino group,
wherein the alkyl group may have one or more substituent(s) selected from the group consisting of a hydroxyl group, a halogen atom, an alkylthio group having 1 to 6 carbon atoms and an alkoxyl group having 1 to 6 carbon atoms, and
Qxe2x80x2 represents a protective group of the amino group or a hydrogen atom); and also relates to the aforementioned compound, its salts or hydrates thereof, wherein the protective group of the amino group is a protective group selected from the group consisting of (substituted) alkoxycarbonyl groups, (substituted) aralkyloxycarbonyl groups, (substituted) acyl groups, (substituted) alkyl groups, (substituted) aralkyl groups and (substituted) silyl groups;
the aforementioned compound, its salts or hydrates thereof, wherein the protective group of the amino group is a protective group selected from the group consisting of a tert-butoxycarbonyl group, a 2,2,2-trichloroethoxycarbonyl group, a benzyloxycarbonyl group, a para-methoxybenzyloxycarbonyl group, a para-nitrobenzyloxycarbonyl group, an acetyl group, a methoxyacetyl group, a trifluoroacetyl group, a chloroacetyl group, a pivaloyl group, a formyl group, a benzoyl group, a tert-butyl group, a benzyl group, a para-nitrobenzyl group, a para-methoxybenzyl group, a (R)-1-phenylethyl group, a (S)-1-phenylethyl group, a triphenylmethyl group, a methoxymethyl group, a tert-butoxymethyl group, a tetrahydropyranyl group, a 2,2,2-trichloroethoxymethyl group, a trimethylsilyl group, an isopropyldimethylsilyl group, a tert-butyldimethylsilyl group, a tribenzylsilyl group and a tert-butyldiphenylsilyl group;
the aforementioned compound, its salts or hydrates thereof, wherein one of R11 and R12 and Qxe2x80x2 are protective groups of the amino group, which are different from each other;
3-(S)-tert-butoxycarbonylamino-4-(S)-fluoromethyl-1-(R)-phenylethylpyrrolidine, its salts or hydrates thereof;
3-(S)-tert-butoxycarbonylamino-4-(S)-fluoromethylpyrrolidine, its salts or hydrates thereof; and
the aforementioned compound, its salts or hydrates thereof, wherein one of R11 and R12 and Qxe2x80x2 are protective groups of the amino group, which are severed under different reaction conditions.
Each of the substituents of the compound of the present invention represented by formula (I): 
(wherein R1, R2, R3 and R4 are as defined in the foregoing) is described in the following.
The substituent R1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, wherein the alkyl group may have one or more substituent(s) selected from the group consisting of a hydroxyl group, a halogen atom, an alkylthio group having 1 to 6 carbon atoms and an alkoxyl group having 1 to 6 carbon atoms.
The alkyl group may be any straight or branched group having 1 to 6 carbon atoms, and its preferred examples include a methyl group, an ethyl group, a normal propyl group and an isopropyl group.
When the alkyl group has a hydroxyl group as a substituent, the alkyl group may be either straight or branched form having 1 to 6 carbon atoms, and the substituting position of hydroxyl group may preferably be on the terminal carbon atom of the alkyl group. Preferred examples of the alkyl group having a hydroxyl group include those which have up to 3 carbon atoms, such as hydroxymethyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl and the like groups.
When the alkyl group has a halogen atom as a substituent, the alkyl group may be either straight or branched form having 1 to 6 carbon atoms, and a fluorine atom is desirable as the halogen atom.
When the alkyl group has an alkylthio group as a substituent, the alkyl group may be either straight or branched form having 1 to 6 carbon atoms, and the alkylthio group may also be either straight or branched form having 1 to 6 carbon atoms. An alkylthiomethyl group, an alkylthioethyl group or an alkylthiopropyl group is desirable as the alkyl group having an alkylthio group, and the alkylthio group may preferably have up to 3 carbon atoms. Its more preferred examples include a methylthiomethyl group, an ethylthiomethyl group and a methylthioethyl group.
When the alkyl group has an alkoxyl group as a substituent, the alkyl group may be either straight or branched form having 1 to 6 carbon atoms, and the alkoxyl group may also be either straight or branched form having 1 to 6 carbon atoms. An alkoxymethyl group, an alkoxyethyl group or an alkoxypropyl group is desirable as the alkyl group having an alkoxyl group, and the alkoxyl group may preferably have up to 3 carbon atoms. Its more preferred examples include a methoxymethyl group, an ethoxymethyl group and a methoxyethyl group.
The substituent R2 is a halogenomethoxyl group or an alkoxyl group having 1 to 6 carbon atoms.
As the halogen of the halogenomethoxyl group, a fluorine atom is particularly desirable, and its number may be from 1 to 3.
The alkoxyl group may be an alkoxyl group having 1 to 6 carbon atoms, preferably a methoxyl group and an ethoxyl group.
Among these substituents, a difluoromethoxyl group and a methoxyl group are preferred, and a methoxyl group is more preferred.
The substituent R3 is an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, a halogenoalkyl group having 1 to 6 carbon atoms, a cyclic alkyl group having 3 to 6 carbon atoms which may have a substituent, a heteroaryl group which may have a substituent, an alkoxyl group having 1 to 6 carbon atoms, an alkylamino group having 1 to 6 carbon atoms or an aryl group which may have one or more substituent(s).
In this case, an ethyl group is desirable as the alkyl group having 1 to 6 carbon atoms. A vinyl or 1-isopropenyl group is desirable as the alkenyl group having 2 to 6 carbon atoms. A 2-fluoroethyl group is desirable as the halogenoalkyl group having 1 to 6 carbon atoms. A cyclopropyl or 2-halogenocyclopropyl group is desirable as the cyclic alkyl group having 3 to 6 carbon atoms which may have a substituent, and a fluorine atom is particularly desirable as the halogen atom of the 2-halogenocyclopropyl group.
Examples of the aryl group which may have one or more substituent(s) include phenyl or the like group which may have 1 to 3 substituents selected from the group consisting for example of fluorine, chlorine, bromine or the like halogen atom, a lower alkyl group having 1 to 6 carbon atoms, a hydroxyl group, an amino group, a nitro group and a lower alkoxyl group having 1 to 6 carbon atoms, and its preferred illustrative examples include a phenyl group, a 2-fluorophenyl group, a 4-fluorophenyl group, a 2,4-difluorophenyl group and a 2-fluoro-4-hydroxyphenyl group.
The heteroaryl group is a group derived from an aromatic heterocyclic compound which contains one or more hetero-atoms selected from a nitrogen atom, an oxygen atom and a sulfur atom. Its examples include pyridyl, pyrimidyl and the like groups. As a substituent on these rings, an alkyl group, a halogen atom or the like is desirable. A methoxyl group is desirable as the alkoxyl group having 1 to 6 carbon atoms. A methylamino group is desirable as the alkylamino group having 1 to 6 carbon atoms.
As the substituent R3, a cyclic alkyl group or a halogenocycloalkyl group is desirable. Among these groups, a cyclopropyl group or a 2-halogenocyclopropyl group is particularly desirable. A fluorine atom is desirable as the halogen atom.
Next, the halogenocyclopropyl group of R3 is described.
As the substituting halogen atom, fluorine and chlorine can be exemplified, and fluorine is particularly preferred.
Stereochemical environment at this moiety with respect to the cyclopropane ring, it is particularly desirable that the halogen atom and the pyridonecarboxylic acid moiety are located in the cis-configuration.
So-called enantiomeric isomers exist solely by the cis-2-halogenocyclopropyl moiety of R3, and strong antibacterial activity and high safety have been observed in all of these isomers.
The present invention exerts excellent characteristics as the substituent represented by formula (VII): 
is substituted at the 7-position of the 6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid nucleus.
The present invention is characterized in that the amino group at the 3-position and the fluoromethyl group at the 4-position on the pyrrolidine ring of this substituent are located in the cis-configuration and absolute configuration of (3S,4S)-form.
That is, it has been found that, when the substituent at the 7-position of the 6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid nucleus is 3-(S)-amino-4-(S)-fluoromethylpyrrolidin-1-yl group, the compound of the present invention shows potent antibacterial activity upon Gram-negative and Gram-positive bacteria and also shows excellent safety and good pharmacokinetics, such as negative property in micronucleus test, markedly weak theophylline metabolism inhibitory activity and the like.
When the compound of the formula (I) of the present invention has a structure in which diastereomers are present, and when such a compound of the present invention is administered to human and animals, it is desirable to administer a compound which comprises a single diastereomer. The term xe2x80x9csinglexe2x80x9d of xe2x80x9ccomprises a single diastereomerxe2x80x9d as used herein means not only a case in which it is completely free from the other diastereomer but also a case in which it is in a chemically pure degree. In other words, it is interpretable that the other diastereomer may be present in such a degree that it does not exert influences upon physical constants and physiological activities of the compound.
Also, the term xe2x80x9cstereochemically purexe2x80x9d as used herein means that, when a compound or the like exists in a plurality of isomer forms due to the presence of asymmetric carbon atoms, the compound is comprised of only one of them. The term xe2x80x9cpurexe2x80x9d in this case can also be considered in the same manner as the term xe2x80x9csinglexe2x80x9d described above.
The 6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid derivative of the present invention may be used either in its free form or as an acid addition salt or a salt of its carboxyl group. Examples of the acid addition salt include hydrochloride, sulfate, nitrate, hydrobromide, hydroiodide, phosphate and the like inorganic acid salts, or acetate, methanesulfonate, benzenesulfonate, toluenesulfonate, citrate, maleate, fumarate, lactate and the like organic acid salts.
The salt of carboxyl group may be either inorganic or organic salt, and its illustrative examples include lithium salt, sodium salt, potassium salt and the like alkali metal salts, magnesium salt, calcium salt and the like alkaline earth metal salts, ammonium salt, or triethylamine salt, N-methylglucamine salt, tris-(hydroxylmethyl)aminomethane salt and the like.
Also, these free form, acid addition salts and salts of carboxyl group of the 6-fluoro-1,4-dihydro-4-oxoquinoline-3-carboxylic acid derivative may be present as hydrates.
On the other hand, a quinolone derivative whose carboxylic acid moiety is an ester is useful as a synthesis intermediate or a prodrug. For example, alkyl esters, benzyl esters, alkoxyalkyl esters, phenylalkyl esters and phenyl esters are useful as synthesis intermediates.
Also, the ester to be used as a prodrug is an ester which is easily cleaved after administered to form free carboxylic acid, and its illustrative examples include acetoxymethyl ester, pivaloyloxymethyl ester, ethoxycarbonyl ester, choline ester, dimethylaminoethyl ester, 5-indanyl ester, phthalidinyl ester, and 5-alkyl-2-oxo-1,3-dioxol-4-ylmethyl ester, 3-acetoxy-2-oxobutyl eater or the like oxoalkyl ester.
The compound of the present invention represented by the formula (I) can be produced by various method, and, in an preferred example of these methods, it can be produced for example by allowing a compound represented by formula (VIII): 
[wherein X1 is a substituent which serves as a leaving group, such as a fluorine atom, a chlorine atom, substituted or unsubstituted phenylsulfonyl group or a substituted or unsubstituted alkylsulfonyl group having 1 to 3 carbon atoms, Y1 is the R4 defined in the formula (I) or a boron-containing group represented by the following formula:
xe2x88x92B(Y11)Y12
(wherein each of Y11 and Y12 is a fluorine atom or an alkylcarbonyloxy group having 2 to 4 carbon atoms), and R2 and R3 are as defined in the formula (I)] to react with a compound represented by formula (IX): 
(wherein R11 and R12, each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a protective group of the amino group,
wherein the alkyl group may have one or more substitutent(s) selected from the group consisting of a hydroxyl group, a halogen atom, an alkylthio group having 1 to 6 carbon atoms and an alkoxyl group having 1 to 6 carbon atoms, or an addition salt thereof (as the acid addition salt, an inorganic acid salt or an organic acid salt can be exemplified, and its illustrative examples include hydrochloride, sulfate, nitrate, hydrobromide, hydroiodide, phosphate and the like inorganic acid salts, or methanesulfonate, benzenesulfonate, toluenesulfonate (sulfonates), acetate, citrate, maleate, fumarate, lactate (carboxylates) and the like organic acid salts).
The reaction can be carried out using or without using a solvent. The solvent to be used in the reaction may be any solvent which is inert under the reaction conditions, and its illustrative examples include dimethyl sulfoxide, pyridine, acetonitrile, ethanol, chloroform, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, water, 3-methoxybutanol and the like or a mixture thereof.
Preferably, the reaction may be carried out in the presence of an acid acceptor such as an inorganic base or an organic base, which includes an alkali metal or alkaline earth metal carbonate or bicarbonate or the like inorganic basic compound, or triethylamine, pyridine, 1,8-diazabicycloundecene or the like organic basic compound.
The reaction temperature may be within the range of generally from room temperature to 200xc2x0 C., preferably from approximately 25 to 150xc2x0 C. The reaction is carried out for a period of from 30 minutes to 48 hours and completes generally after about 30 minutes to 20 hours.
Examples of the protective group of the amino group to be used in the compound represented by the formula (IX) include those which are generally used in this field, such as tert-butoxycarbonyl, 2,2,2-trichloroethoxycarbonyl and the like (substituted) alkoxycarbonyl groups, benzyloxycarbonyl, para-methoxybenzyloxycarbonyl, para-nitrobenzyloxycarbonyl and the like (substituted) aralkyloxycarbonyl groups, acetyl, methoxyacetyl, trifluoroacetyl, chloroacetyl, pivaloyl, formyl, benzoyl and the like (substituted) acyl groups, tert-butyl, benzyl, para-nitrobenzyl, para-methoxybenzyl, triphenylmethyl and the like (substituted) alkyl groups or (substituted) aralkyl groups, methoxymethyl, tert-butoxymethyl, tetrahydropyranyl, 2,2,2-trichloroethoxymethyl and the like ethers and trimethylsilyl, isopropyldimethylsilyl, tert-butyldimethylsilyl, tribenzylsilyl, tert-butyldiphenylsilyl and the like substituted silyl groups (the term xe2x80x9c(substituted)xe2x80x9d as used herein means xe2x80x9cwhich may have a substituentxe2x80x9d).
When Y1 is an alkyl group having 1 to 6 carbon atoms, an alkoxymethyl group having 2 to 7 carbon atoms or a phenylalkyl group composed of an alkylene group having 1 to 6 carbon atoms and a phenyl group, the compound of interest can be converted into its corresponding carboxylic acid by treating it under an acidic or basic condition which is generally employed for the hydrolysis of carboxylic acid esters.
When Y1 is a boron-containing group of the formula:
xe2x88x92B(Y11)Y12,
its conversion into corresponding carboxylic acid can be effected by allowing a compound represented by the formula (IX) to react with a compound of the formula (VIII) and then treating it under an acidic or basic condition.
In addition, when deprotection is necessary, the compound of interest represented by the formula (I) can be obtained by removing the protective group by selecting suitable conditions for the protective group.
The compound represented by the formula (VIII) can be produced by already known methods. Also, a compound in which Y1 is a boron-containing group can be obtained by allowing the carboxylic acid or a ester derivative thereof to react with a boron fluoride compound or anhydrous boron carboxylate.
In the compound in which Y1 is a boron-containing group, each of Y11 and Y12 is a fluorine atom or an acyloxy group. The acyloxy group may be either aliphatic (becomes an alkylcarbonyloxy group) or aromatic, and either may have an additional substituent. As such a substituent, it may have one or more substituent(s) selected from the group consisting of a halogen atom, an alkyl group having 1 to 6 carbon atoms and an alkoxyl group having 1 to 6 carbon atoms. Examples of the acyloxy group include acetyloxy, propanoyloxy, butanoyloxy, benzoyloxy, phenylacetyloxy and the like groups, of which an acyloxy group having 2 to 4 carbon atoms (an alkylcarbonyloxy group) is preferred and an acetyloxy group is particularly preferred.
The compound represented by the formula (IX) can be formed by removing Qxe2x80x2 from the compound of formula (II): 
[wherein R11 and R12, each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a protective group of the amino group,
wherein the alkyl group may have one or more substituent(s) selected from the group consisting of a hydroxyl group, a halogen atom, an alkylthio group having 1 to 6 carbon atoms and an alkoxyl group having 1 to 6 carbon atoms, and
Qxe2x80x2 represents a protective group of the amino group or a hydrogen atom, and
wherein the amino protective group may be a protective group selected from the group consisting of (substituted) alkoxycarbonyl groups, (substituted) aralkyloxycarbonyl groups, (substituted) acyl groups, (substituted) alkyl groups, (substituted) aralkyl groups and substituted silyl groups.]
The compound represented by the formula (IX) and the compound represented by the formula (II) can be produced by various method. For example, 3-(S)-tert-butoxycarbonylamino-4-(S)-fluoromethylpyrrolidine can be synthesized in accordance with the method described as a desirable method in Reference Examples, though not particularly limited.
The compound represented by the formula (II) can also exist in the form of a salt thereof, a hydrate thereof or a hydrate of the salt. Examples of its acid addition salt include an inorganic acid salt or an organic acid salt, and its illustrative examples include hydrochloride, sulfate, nitrate, hydrobromide, hydroiodide, phosphate and the like inorganic acid salts, or methanesulfonate, benzenesulfonate, toluenesulfonate (sulfonates), acetate, citrate, maleate, fumarate, lactate (carboxylates) and the like organic acid salts.
When one of R11 and R12 is a protective group of the amino group and Qxe2x80x2 is also a protective group of the amino group, these groups may be the same or different from each other, but it is convenient to obtain a compound in which each of them is removed under different reaction condition, namely one of them is selectively removed but the other remains un-removed, for the production the compound (I).
The following can be exemplified as R11 or R12 (either one of them) and Qxe2x80x2 which are the protective groups of the amino group. That is, they are (substituted) alkoxycarbonyl groups, (substituted) aralkyloxycarbonyl groups, (substituted) acyl groups, (substituted) alkyl groups, (substituted) aralkyl groups and substituted silyl groups.
Their illustrative examples include tert-butoxycarbonyl, 2,2,2-trichloroethoxycarbonyl and the like (substituted) alkoxycarbonyl groups, benzyloxycarbonyl, para-methoxybenzyloxycarbonyl, para-nitrobenzyloxycarbonyl and the like aralkyloxycarbonyl groups, acetyl, methoxyacetyl, trifluoroacetyl, chloroacetyl, pivaloyl, formyl, benzoyl and the like (substituted) acyl groups, tert-butyl, benzyl, para-nitrobenzyl, para-methoxybenzyl, triphenylmethyl and the like (substituted) alkyl groups or (substituted) aralkyl groups, methoxymethyl, tert-butoxymethyl, tetrahydropyranyl, 2,2,2-trichloroethoxymethyl and the like ethers and trimethylsilyl, isopropyldimethylsilyl, tert-butyldimethylsilyl, tribenzylsilyl, tert-butyldiphenylsilyl and the like substituted silyl groups.
Cis-2-fluorocyclopropylamine comprised of a single isomer which is desirable for the synthesis of the compound of the formula (I) comprised of a single isomer can, for example, be synthesized by the method described in JP-A-2-231475. Synthesis of the compound of the formula (I) comprised of a single isomer can, for example, be carried out in accordance with the method described in JP-A-2-231475, using the thus obtained optically active cis-2-fluorocyclopropylamine derivative as the material.
Since the compound of the present invention has potent antibacterial activities, it can be used as medicaments for use in human bodies, animals and fishes or as preservatives of agricultural chemicals and food.
When the compound of the present invention is used as a medicament for human bodies, its dosage may be within the range of generally from 50 mg to 1 g, preferably from 100 mg to 300 mg, per day per adult.
Its dosage as a drug for animals varies depending on the purpose of its administration (treatment or prevention), kind and size of each animal to be treated and kind and degree of each infected pathogenic bacterium, but the dosage may be within the range of generally from 1 mg to 200 mg, preferably from 5 mg to 100 mg, per 1 kg body weight per day.
The daily dose may be used once a day or by dividing it into 2 to 4 doses per day. As occasion demands, the daily dose may exceed the aforementioned range.
Since the compound of the present invention has activity against a broad range of microorganisms which cause various infectious diseases, it can treat, prevent or alleviate diseases induced by these pathogens.
Illustrative examples of bacteria or bacterioid microorganisms on which the compound of the present invention is effective include those which belong to the genus Staphylococcus, Streptococcus pyogens, hemolytic streptococcus, enterococcus, pneumococcus, those which belong to the genus Peptostreptococcus, Neisseria gonorrhoeae, Escherichia coli, those which belong to the genus Citrobacter, those which belong to the genus Shigella, Klebsiella pneumoniae, those which belong to the genus Enterobacter, those which belong to the genus Serratia, those which belong to the genus Proteus, Pseudomonas aeruginosa, Haemophilus influenzae, those which belong to the genus Acinetobacter, those which belong to the genus Campylobacter, Chlamydia trachomatis and the like.
Illustrative examples of diseases which are induced by these pathogens include folliculitis, furuncle, carbuncle, erysipelas, phlegmon, lymphangitis, felon, subcutaneous abscess, hidradenitis, acne conglobata, infectious atheroma, perirectal abscess, mastitis, superficial secondary infections after injury, burn injury, operative wound and the like, pharyngitis, acute bronchitis, tonsilitis, chronic bronchitis, bronchiectasis, diffuse bronchiolitis, secondary infection of chronic respiratory disease, pneumonia, pyelonephritis, cystitis, prostatitis, epididymitis, gonococcal urethritis, nonspecific urethritis, cholecystitis, cholangitis, bacillary dysentery, enteritis, uterine adnexitis, intrauterine infection, bartholinitis, blepharitis, hordeolum, dacryocystitis, tarsadenitis, corneal ulcer, octitis media, sinusitis, periodentitis, pericoronitis, jaw infection, peritonitis, endocarditis, sepsis, meningitis, skin infection and the like.
The compound of the present invention is also effective against various microorganisms which cause infectious diseases in animals, such as those which belong to the genera Escherichia, Salmonella, Pasteurella, Haemophilus, Bordetella, Staphylococcus, Mycoplasma and the like.
Illustrative examples of such diseases include colibacillosis, pullorum disease, avian paratyphoid, avian cholera, infectious coryza, staphylococcosis, mycoplasma infection and the like in the case of birds; colibacillosis, salmonellosis, pasteurellosis, haemophilus infection, atrophic rhinitis, exudative epidermis, mycoplasma infection and the like in the case of pigs; colibacillosis, salmonellosis, hemorrhagic sepsis, mycoplasma infection, bovine pleuropneumonia, bovine mastitis and the like in the case of cattle; colisepsis, salmonella infection, hemorrhagic sepsis, uterine empyema, cystitis and the like in the case of dogs; and exudative pleurisy, cystitis, chronic rhinitis, haemophilus infection, kitten diarrhea, mycoplasma infection and the like in the case of cats.
The antibacterial preparation which comprises the compound of the present invention can be prepared by selecting appropriate preparation depending on each administration method and employing generally used various preparation method. With regard to the dosage forms of the antibacterial preparation which uses the compound of the present invention as its principal agent, tablets, powders, granules, capsules, solutions, syrups, elixirs, oily or aqueous suspensions and the like can be exemplified as oral preparations.
With regard to injections, a stabilizing agent, an antiseptic agent, a solubilizing agent and the like may be used in the preparation, and a solution which may contain these auxiliary agents may be contained in a container and made into a solid preparation by freeze-drying or the like means to be re-dissolved when used. In addition, a single dose may be contained in a single container or multiple doses may be contained in the same container.
Also, solutions, suspensions, emulsions, ointments, gels, creams, lotions, sprays and the like can be exemplified as preparations for external use.
Solid preparations may contain pharmaceutically acceptable additives together with the active compound and can be prepared for example by mixing the compound with additives optionally selected from fillers, extenders, binders, disintegrators, solubilization enhancing agents, moistening agents, lubricating agents and the like.
As liquid preparations, solutions, suspensions, emulsions and the like can be exemplified, which may contain a suspending agent, an emulsifying agent and the like as additives.
Examples of the method for administering the compound of the present invention to animals include a method in which it is orally administered directly or by mixing it with feed, a method in which it is made into a solution and then orally administered directly or by mixing it with drinking water or feed and a method in which it is administered by injection.
With regard to the pharmaceutical preparations for use in the administration of the compound of the present invention to animals, it can be made optionally into powders, fine subtilaes, soluble powders, syrups, solutions or injections making use of the techniques generally used in this field.
Formulation examples of the pharmaceutical preparations are shown below.
Examples of the present invention are given below by way of illustration and not by way of limitation. The antibacterial activity of each compound of interest was measured in accordance with the standard method specified by the Japan Society of Chemotherapy, with the results shown in Table 1 as MIC values (xcexcg/ml).